Refrigeration



G m N N E L A REFRI GERATI ON Filed April 16, 1935 3 Sheets-Sheet l v un EVENTOR,

A ZORNEY.

A LENNENG Dec. 27, 1%38.

REFRIGERATION Filed April 16, 1935 3 Sheets-Sheet 2 XXX mv NTOR, mac Vi? 4+ ATTORNEY.

A. LENNING Dec. 27, 1938.

REFRIGERAT I ON Filed April 16, 1935 3 Sheets-Sheet 3 61 i wwwj INVENTOR, 4. 95

W A A TTORINEY.

Patented Dec. 27, 1938 REFRIGERATION Alva: Lenning, Stockholm, Sweden, assignor, by

mesne assignments, to

Servel, Inc., Dover, Del.,

a corporation of Delaware Application April 16, 1935, Serial No. 16,540

16 Claims.

My invention relates to absorption refrigerating apparatus and systems, more particularlyto refrigerators having air cooled absorbers and condensers, and still more particularly to such apparatus employing an inert gas for equalizing pressure.

One of the objects of my invention is to provide a compact and efllcient direct air cooled system. Another object is to provide an im-. proved boiler or generator in a system of the absorption type using inert gas. Another object is to provide compactness of unit in a refrigerator and to reduce the external dimensions thereof. Another object is to provide an efficient evaporator arrangement. Another object is to provide effective natural draft air cooling of an absorber in an absorption system and independence of cooling of absorber and condenser.

Further objects and advantages of the invention will be apparent from the following description of a preferred form of the invention taken in conjunction with the accompanying drawings forming a part of this specification and of which:

Fig. 1 is a vertical cross-sectional view through a refrigerator embodying the invention. This figure is taken onthe lines l-l of Figs. 2, 3, 4 and 5;

Fig. 2 is a vertical sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a top horizontal view with the'top cover of the, refrigerator removed;

Fig. 4 is a horizontal cross-sectional view taken on the line 4--4 of Fig. 1;

Fig. 5 is a horizontal cross-sectional view taken on the line 5-5 of Fig. 1; and

Fig. 6 is a detail vertical sectional view taken on the line 6-6 of Figs. 2 and 4.

Numeral l represents generally a refrigerator cabinet in which there is a food space H surrounded by walls 12 suitably insulated. Access to the food space is had through an insulated door l3.

Below the food space is an apparatus compartment 14. Behind the food space is a flue l closed at the rear by a rear panel 2!. Above the food space is a condenser compartment 16 which extends the full width and depth of the refrigerator cabinet and which may be open at the top or which may have an apertured cover.

Within the apparatus compartment is a generator l1. The generator may be heated by means of a gas burner l8 suitably controlled in response to variations of temperature of the food space or the evaporator therein. Products of combustion formed in the generator jacket 19 pass through chimney 20 and leave at the top of the cabinet. The generator, which is formed as a cylinder having rounded ends and disposed on a vertical axis, is separated into an upper chamber 22 and a lower chamber 23 by means of a horizontal partition or plate 24. Within chamber 23 is a percolator pocket 25 consisting of an inverted cup. A gas lift or percolator tube 26 extends down within pocket 25 and extends upwardly and passes through partition 24 and opens within chamber 22 near the top thereof. Within chamber 22 is an overflow and vapor tube 21 which also extends through partition 24.

.A relatively large conduit 28 is connected to chamber 23 and extends horizontally an appreciable distance towards the back end of the cabinet and thence extends upwardly and communicates with upwardly inclined branches 29 and 30 at the upper part of flue l5 which in turn are connected with forwardly extending condenser tubes 3! and 32. The condenser tubes incline downwardly to the front side of the cabinet and are surrounded by metal plates or. fins 33 whereby they may be cooled by air. Louvres 34 are formed in the lateral and front side walls of the condenser compartment it so that air may have access to the condenser. It will be noted that the condenser is generally of U-shape with the legs of the U extending upwardly over the food space and the condenser cooling is independent of flow of air upwardly through the flue i5.

Tubes 35 and 36 are connected to the front ends of condenser tubes 3| and 32 for draining liquid refrigerant therefrom and extend downwardly into a. gas heat exchanger 31 and within a tube 38 which extends through a removable wall portion 39 and into the food space.

Within the food space is an evaporator generally designated 40, including an inner casing 4|. Situated within this inner casing are compartments 42 for reception of ice trays. Surrounding the compartments 42 is an" evaporator tube or coil 43 which communicates with and is a continuation of pipe 38. The evaporator tubing extends inwardly from thegas heat exchanger and into the casing 4|, has a loop above the ice drawer compartments, and then extends obliquely to a point below the ice drawer compartments and has another turn below the ice drawer compartments. Thence this tubing extends to behind the casing 40 and a horizontal heating portion 44 has fins thereon and constitutes a high temperature evaporator section. Thence the tubing extends as shown at 45 in Fig. 6 to a space 41 of the gas heat exchanger 31.

Surrounding the inner casing 4| and the high temperature evaporator section 44 is asheet metal casin 49 having front apertures 50 in alignment with theice drawer compartments and lower apertures 5| and 52 for circulation of air. This outer evaporator casing 49. may be porcelained.

In the apparatus compartment I4 below the food space is an absorber consisting of tubing Hi. This tubing is substantially in one horizontal plane. There are two U-bends forming parts of this tubing laterally to each side of the generator ll. Fins H are provided on the absorber and the front and lateral side walls of the apparatus compartment are provided with louvres I2 to admit air thereto for cooling the absorber. Also the bottom of the apparatus compartment .may be open to admit air for cooling and for combustion. One end of the absorber tubing is connected to one of separatedspaces of the gas heat exchanger and the other end of the tubing 10 is connected to another of separated spaces of the gas heat exchanger 31.

The gas heat exchanger consists of a vertical cylindrical member having semi-spherical ends and divided internally by two plates 55, 56 and tubes 51 passing through the two plates so that one space 47 is formed around the tubes and another space is formed within the tubes and including spaces at the ends.

Connected to the bottom of the heat exchanger is a rich absorption liquor pipe 58 which is formed into a coil surrounding apart of the generator and is connected at 59 near the rear of the cabinet to the conduit 28. A liquid tube 60 surrounds conduit 58 and forms a liquid heat exchanger therewith. One end of conduit 60 is connected by means of a tube 6| with chamber 22 while the other end is connected to the absorber by means of a tube 52.

The apparatus or unit is mounted on the removable wall section 39 and is removable as a whole from the cabinet by removing the rear panel 2|.

The unit, which consists of steel tubing suitably welded so as to be hermetically sealed, includes a solution of ammonia or other refrigerant in water or other absorption liquid and contains an inert gas such as hydrogen. The general operation of the unit is like that disclosed in U. S. Patent No. 1,609,334 of Dec. 7, 1926 to von Platen and Munters. Heat applied to the generator causes expulsion of ammonia vapor from solution. Some of the vapor passes directly from chamber 23 into pipe 28. Other vapor is trapped in the pocket 25 and causes lifting of liquid through pipe 26 to the upper chamber 22. Vapor separated from the liquid in the upper chamber 22 passes downwardly through tube 21 and joins the vapor formed in chamber 23 to pass through pipe 28. The ammonia vapor passes upwardly through pipe 28 and enters the condenser tubes 3|, 32 where it is liquefied. The liquid ammonia flows through conduits 35, 36 into conduit 38 and into the evaporator. Here the liquefied ammonia meets the inert gas passing upwardly through the heat exchanger 31 and also entering tube 38. The liquid ammonia evaporates and diffuses into the hydrogen, thus absorbing heat and producing refrigeration which serves to freeze ice in the ice drawers or compartments and to chill the food space. The

liquid ammonia and hydrogen flow downwardly within the tube 43 and tube 44 and into the space of the heat exchanger surrounding the tubes 51. A heavy mixture of ammonia gas and hydrogen is formed in the evaporator, which due to gravity, flows downwardly through the heat exchanger and into the absorber 10. Weak liquid passes into the absorber through conduit 62 and absorbs the ammonia vapor, forming what is known as strong liquor. The strong liquor flows into conduit 58 and thence through the liquid heat exchanger and enters conduit 28 at 59.

Here the strong liquor meets the generated vapor and cools the generated vapor to remove entrained absorption liquid vapor therefrom and is in turn heated. The horizontal portion of conduit 28 thus constitutes an eflicient analyzer and rectifier. The absorption liquid passes directly into the generator chamber 23 from conduit 28 and is lifted through percolator tube 26 and flows from chamber 22 back to the absorber through conduits GI, 60 and 62. Hydrogen deprived of ammonia vapor,.being relatively light, flows upwardly from the absorber through the tubes 51 of the gas heat exchanger and back to the evaporator. Air in'the food space is circulated around the evaporator through the openings 5| and 52 and thus a directed circulation is provided.

It will be seen that the unit is simple in design and affords direct air cooling of the absorber and condenser without interference to the cooling of one by the other. The back flue of the cabinet can be relatively narrow and can be closed so as to give a good natural draft effect. This is accomplished without interfering with the cooling of the condenser. Also indirect cooling means are avoided and no conduit part of the heat dissipating surface is behind another in the path of air. All of the conduit branches of the absorber are in parallel with respect to air flow and each of the branches'is exposed to air of the same cooling value, that is, air of entrance temperature with respect to the path of-air flow, unheated by previous dissipation of heat of absorption. The condenser and absorber are positioned in the cabinet so as to best utilize the space thereof and to be most effective. The particular generator arrangement allows of a low apparatus compartment. The strong liquor is effectively utilized for analyzing purposes.

While I have described one embodiment of my invention it will be understood that variations may be made within the scope of the invention.

I claim:

1. In absorption refrigerating apparatus, a generator including a lower gas and liquid chamber and an upper gas and liquid chamber, means to lift liquid from said lower chamber to said upper chamber, an overflow pipe communicating with said upper and lower chambers, a horizontal vapor oiftake conduit connected to the gas space of the lower chamber, and means to flow absorption liquid along said offtake conduit.

2. In absorption refrigerating apparatus, a generator consisting of a vertically disposed cylindrical vessel, a partition dividing said vessel into an upper gas and liquid chamber and a lower gas and liquid chamber, gas lift means to raise partment below said food compartment, wall members forming a flue at the rear of said cabinet communicating with saidapparatus compartment, a generator within said apparatus compartment, and an air cooled absorber in said apparatus compartment including a tubular conduit having a portion coiled in a substantially horizontal plane on each side of said generator.

4. In absorption refrigerating apparatus, a cabinet having a rear narrow flue, an insulated food compartment in front of said flue, a tubular direct air-cooled condenser above said food compartment, and a direct air cooled absorber comprising a conduit coiled in a single substantially horizontal plane and located below said food compartment.

5. In an absorption refrigerating system, a condenser, a conduit for conducting vapor to said condenser having a horizontal portion, means to lift absorption liquid from an elevation below said horizontal portion to an elevation above said horizontal portion, an absorber, means to conduct absorption liquid from said absorber to said horizontal portion and thence to said lower elevation, and means to conduct liquid from. said higher elevation to said absorber in heat exchange relation wii 1 the liquid flowing to said horizontal portion.

6. An absorption refrigeration system including a generator having a lower gas and liquid chamber and a higher gas and liquid chamber, a first member for conducting strong solution to said lower chamber, a second member for conducting weak solution from said higher chamber, means to lift solution from said lower chamber to said higher chamber, means to conduct vapor from said higher chamber to said lower chamber, and a vapor offtake conduit connected to said lower chamber including said first member. A

7. An absorption refrigeration system including a generator consisting of an upright cylindrical vessel having a horizontal partition dividing the same into a lower gas and liquid chamber and an upper gas and liquid chamber, an inlet connection for admitting strong solution to said lower chamber, an outlet connection for withdrawing weaksolution from said upper chamber, a conduit for vapor from said upper chamber to said lower chamber, means to lift solution from said lower chamber to said upper chamber, and a vapor offtake connection to said lower chamber.

8. Absorption refrigeration apparatus including an upper condenser comprising a tubular conduit having turns in a single substantially horizontal plane, alower absorber comprising a tubular conduit coiled in a single substantially horizontal plane, and an evaporator comprising a tubular conduit above said absorber and below said condenser, and conduits connecting said three tubular parts and extending vertically at one side thereof.

9. A refrigerator including a cabinet having three superposed compartments, absorption refrigeration apparatusincluding anupper condenser comprising a tubular conduit having turns in a single substantially horizontal plane, a lower absorber comprising a tubular conduit having turns in a single substantially horizontal plane, and an evaporator intermediate said condenser and absorber and comprising a tubular conduit, and members'connecting said tubular conduits and located at one side thereof so that said apparatus may be inserted in said cabinet with said lower absorber, the intermediate evaporator, and the upper condenser located respectively in the superposed compartments of the cabinet.

10. An absorption refrigeration system including a generator having a first gas and liquid chamber and a second gas and liquid chamber, means for flowing solution from one to another of said chambers, a member for'conducting weak solution from said second chamber, a conduit for conducting strong solution to said flrst chamber and vapor from said first chamber in the presence of each other, and means to conduct vapor from said second chamber to said conduit.

11. In an absorption refrigerator, a cabinet having superposed compartments, an evaporator situated within an intermediate compartment of said cabinet, a flue at the rear of said cabinet,

a conduit in said flue, finned condenser sections in an upper compartment of said cabinet and connected to said conduit, a generator in a lower compartment of said cabinet and connected to said conduit, an absorber comprising a conduit coiled in a single substantially horizontal plane at the bottom of said flue and connected to said generator, said flue providing draft ,for said absorber, and said cabinet having louvers for passage of air to cool said condenser sections.

12. An absorption type refrigerator including a generator, a condenser, an evaporator, an absorber, interconnecting conduits forming circuits for circulation of a refrigerant, ablorption liquid and an inert gas, a cabinet including an insulated food compartment, an apparatus compartment and a flue communicating with said apparatus compartment, said absorber comprising a conduit having turns in a single substantially horizontal plane and having fins thereon for direct air-cooling and being situated at the lower end of the flue, said condenser having flns thereon for direct air-cooling and being situated at the upper end of the flue, and said evaporator being situated in said food compartment and having flns thereon for directly cooling the food compartment.

13. In absorptionrefrigerating apparatus, an insulated food compartment, an apparatus compartment below said food compartment, wall members forming a flue at the rear of said cabinet communicating with said apparatus compartment, a generator within said apparatus compartment, and a direct air-cooled absorber comprising essentially a tubular conduit disposed in said apparatus compartment and having a plurality of heat-dissipating conduit branches in a single substantially horizontal plane, all of said branches being substantially in parallel with respect to air flow and each of said branches being exposed to cooling by air of entrance temperature, unheated by previous dissipation of heat of absorption, at least a major portion of the absorber having its conduit portions nonoverlapping with respect to air flow.

14. An absorption refrigeration system including a generator, a condenser, an evaporator, an absorber, and members connecting said parts for circulation of refrigerant through the parts, for circulation of absorption liquid between the generator and the absorber and circulation of inert gas between the absorber and the evaporator, said absorber having heat rejecting surface provided by a finned conduit having branches all of which are in a single substantially horizontal plane, and members forming a path for upward flow of air in cooling relation with said absorber so that all parts of the absorber are substanuid and a pressure equal zing medium, said system including means for circulating the pressure equalizing medium between the absorber and the evaporator, said absorber comprising a sinuous conduit including branches disposed in a single substantially horizontal plane, and members forming a path for flow of air in cooling relation with said absorber, said absorber being arranged so that all parts or said conduit in the path of-flow of air are substantially in parallel with respect to the air flow, each of said branches being exposed to cooling by air of entrance temperature, unheated by previous dissipation of heat of absorption. I

16. In an absorptionreifrlgerating apparatus,

an insulated food compartment, an apparatus compartment below said iood compartment,

members forming a draft producing flue laterally" of said food compartment and communicating with said apparatus compartment, and a direct air-cooled absorber in said apparatus compartment, said absorber comprising a sinuous conduit including a plurality of branches disposed in a single substantially horizontal plane and being arranged so that all parts oi said branches in the path of flow or air produced by said flue are tions non-overlapping with respect to air flow.

- ALVAR LENNING. 

